The present invention relates generally to power supply systems and methods, and more particularly to a power supply system and method for a linear stator motor.
DE-B 23 10 812 discloses a power supply system for magnetic suspension vehicles, in which the stator winding of the linear stator motor is divided into several switching segments along the travel path. The switching segments are alternately assigned to a first and a second cable route system. The switching segments and the cable route systems can be switched via switching devices (e.g. contactors) to controllable power supply devices, which are usually arranged in transformer substations. In the switching segments, a revolving field voltage U.sub.p is then induced by the vehicle in each case which supplies a thrust F.about.U.sub.p .times.I, where I is the input current.
This power supply system operates according to the leap frog control method. Here, a differentiation is made between a short route (or secondary) with only one transformer substation, and a long route with more than one substation along the travel path.
In the case of secondary or short routes with two cable route systems, two power supply devices (e.g. converters) are arranged in a single substation. Each converter is arranged in a cable route system. The switching segments are alternately rigidly assigned to one of the two cable route systems, and can be switched on or off via contactors. In each case, the switching segment in which the vehicle is located is switched on and supplied from one of the two converters. When changing switching segments, the converter which was previously inactive becomes active, and supplies the following switching segment.
In the case of long routes with two cable route systems, at least two converters are housed in each of the substations. The switching segment in which the vehicle is located is simultaneously supplied from two converters from adjacent substations. When changing switching segments, the other two (previously shut off) converters of the same substations are activated and supply the following switching segment.
In the previous power supply systems, one of the two converters is therefore not utilized, both for short and for long routes--aside from changes in switching segments. Furthermore, each of the cable route systems are only utilized for approximately 50% of the total operating time.